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|From:||Leonardo Francalanci||Date:||June 21 2004 4:57pm|
|Subject:||why CPU is high while disks are idle in a table scan???|
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I'm doing some tests on a 16.000.000 rows table. Doing a simple "SELECT SUM(MYFIELD) FROM MYTABLE" I noticed that disks are at 0.1%, while cpu arrives up to 80%. How is that possible? My HDs are IDE. MySql has around 30Mb of ram, I thought it should read a lot from disk. Even doing lots of queries by key I get only high cpu usage, not disk reads. Is that normal?